1. Field of the Invention
The invention relates to a waterproof shoe, more particularly to a waterproof shoe with an inner liner which is made of a water impervious but vapor-permeable material disposed inside an upper and which has a bottom open end bonded to the upper.
2. Description of the Related Art
Conventional waterproof shoes generally include an outer shell made of a waterproofing material which is impervious to both air and vapor. Such waterproof shoes tend to cause discomfort to the wearer, as ventilation of perspiration vapors gathered around the wearer""s feet is not permitted. Improvements available in the art for coping with such perspiration problems include the use of a non-waterproof material, such as leather or fabric, for the outer shell of an upper and the use of a sock-like liner, which is made of a material or laminate impervious to water but pervious to perspiration vapor, as a protection part for the foot against water intrusion. In particular, shoe constructions with such an improvement generally include a sock-like liner which has a top open end secured to the top open end of an upper, and a bottom wall seated on and bonded adhesively to a midsole which is secured to the bottom end of the upper. A disadvantage found in such constructions is that water can seep into the interior of the shoe through the seams of the shoe and can be trapped in the space between the upper and the sock-like liner.
Attempts have been made in order to alleviate the aforesaid water seeping problems by improving the waterproofing characteristics of the waterproof breathable shoes. U.S. Pat. No. 5,678,326 suggests an improved shoe construction which comprises an outer shell connected to an insole, a waterproof, water-vapor permeable shoe insert disposed inside the outer shell, and a lining provided inside the shoe insert. Both of the lining and the shoe insert have their bottom walls extending between an outsole and an insole, and are secured to the bottom portion of the upper and to the outsole and insole by using several layers of adhesive.
As described herein above, the prior art addressed the aforesaid water seeping problem by focusing on improvements on the waterproofing characteristics of the shoes. The technical measures taken in the art to enhance the waterproofing characteristics, however, tend to reduce the ventilating characteristics and vapor permeability of shoes.
U.S. Pat. No. 6,065,227 discloses a waterproof boot construction designed to provide a drain outlet for the water invading the boot. The boot construction as disclosed therein comprises an outer shell having an upper of non-waterproof material, and a lower of waterproof material and utilizes a waterproof, water-vapor permeable inner lining sleeve to line the upper. The bottom ends of the upper and the lining sleeve are stitched to a top end of the lower, and a water-tight seal is provided inside the lining sleeve and the lower so that the water seeping through the stitched seam into the space between the lining sleeve and the upper is prevented from invading the interior of the lining sleeve and the lower and is diverted to the stitched seam for drainage. The drain outlet formed as such is located along the stitched joint of the overlapping parts of the upper and the lower of the boot.
U.S. Pat. No. 4,599,810 discloses stitchdown shoes which incorporate waterproof, vapor permeable sock-like liners and which provide good ventilating property. In the construction of these shoes, although a stitchdown formed at the joint of a midsole and an upper permits ventilation, since a padding, which is typically made of a fibrous or foamed material, is disposed between the inner surface of the upper and the sock-like liner, the water penetrating through the stitchdown can be retained in the padding due to the water-wicking property of the padding. The wet padding not only adds weight to the shoe but also reduces the warmness of the shoe. On the other hand, the sock-like liner used in this shoe construction has a bottom wall which is seated on a midsole and is secured adhesively thereto. The need to provide the liner with the bottom wall complicates the process of making the shoe and increases the consumption of expensive waterproof, vapor permeable material. The procedure for securing adhesively the bottom wall of the liner to the midsole is also cumbersome and time-consuming.
An object of the present invention is to provide a waterproof shoe which permits the wearer""s feet to breathe.
Another object of the present invention is to provide a waterproof breathable shoe which can be produced via a less complicated process with reduced consumption of expensive waterproof breathable material.
According to the present invention, a waterproof shoe includes an insole, an upper having a top open end and a bottom open end secured to the insole, and a lining sleeve disposed inside the upper. The lining sleeve has a top open end connected to the top open end of the upper, and a bottom open end extending along an inner surface of the upper and ending at a distance from and above the bottom open end of the upper. The lining sleeve is made of a material, which is impervious to water but is pervious to perspiration vapor. Waterproof means is adhesively attached to and bonds together the upper and the lining sleeve.